Gas-separation process



NOV. 18V, 1930. G CLAUDE 1,782,287

' GAS SEPARATION PROCESS l Filed May 8.` 1925 Patented Nov. 18, 1930 pUNITED STATES PATENT ori-ICE GEORGES CLAUDE, -oF PARIS, FRANCE, AssIGNoRTo SOCIETE LAIR LIQUIDE, SOCIETE ANONYME POUR LETUDE ET LExrLoI'rATIoNDEs PRocEDEs GEORGES CLAUDE, 0E

PARIS, FRANCE GAS-SEPARATION PROCESS Application led May 8, 1925, SerialNo. 28,940, and in France June-3, 1924.

This invention relates to the manufacture of hydrogen by the partialliquefaction of gaseous mixtures containing hydrogen and nitrogen, suchas coke oven gases, ordinary illuminating gas or the like.

It has been observed that owing to the nitrogen contained in these gasesbeing the most diiiicultly liquefiable of the constituents other 'thanhydrogen, the liquid nitrogen outside the said nest of tubes, may4contain f a considerable proportion of nitrogen which is altogetherlost so far as concerns the washing of the carbon monoxide and also theproduction of ammonia, if the gaseous mixture produced is intended to beused.

The object of the present invention is to avoid such loss of nitrogenas-above referred to and thus to improve the eificienc of the processwith regard to the purity oy the hydrogen obtained thereby. For thispurpose according to the present invention the process for themanufacture of hydrogen by partial liquefaction of mixtures of gasescontaining the same is characterized in that the liquid containingnitrogen produced during the course of thev partial liquefaction issubjected in an auxiliary rectification column to a pro'- gressiverectification or vaporization whilst under the same pressure as that atwhich the partial liquefaction of the gases is effected, the gas rich innitrogen vthus obtained returning to the place where the nitrogencontaining liquid is produced and the liquid substantially free fromnitrogen produced as a result of the said progressive rectificationbeing used fo'r bringing about by its vapor-4 ization the said partialliquefaction.

1n order that the said invention may be clearly understood and readilycarried into effect, the same will now be described 'more K 1 The columnA in which the progressive 55 partial liquefaction of the gases iseffected is provided with the upper nest of tubes'B vfor the finalliquefaction beneath and to one side of which is located a rectifyingcolumn C in open communication with the collector D arranged at thebottom of the nest of tubes B. At the lower part of the column C thereis provided a vaporizer V connected with which is a pipe E.

The compressed gaseous mixture to be treated, after having beenpreviously cooled -to a low temperature, is delivered to thecom moninlet pipe G; the greater portion; of the gases ascends through thelower nest of tubes H 'in the column A, whence the gases passdo into theupper nest of tubes B. The liquid formed in these latter tubes B,containing a certain proportion of nitrogen, falls into the collectorVD, and thence descends over the successive plates of the rectificationcolumn 'I5 C; during this descent it becomes rectified by- Contact withthe ascending vapors and nally reaches the vaporizer V entirely oralmost entirely freed from nitrogen; the liquid from the vaporizer Vis'discharged through the 80 pipe E into the compartment I outside thenest of tubes B. The heating of the liquid in the vaporizer at thebottom of the column C is effectedv by a part of the compressed -gasesto be treated which are delivered through the pipe K from the commoninlet pipe G. The' gaseous residue from the liquefaction of thecompressedgases which pass through the nest of tubes in thevaporizer Vis returned to thel principal column A, for

example by passage through the pipe Z into the collector D. The liquidformed by the liquefaction which takes place-inside the nest of tubes ofthe vaporizer V, being only a small quantity, can be allowed topassthrough the pipe Land thereb mix with the liquid which collects atthev gottom of thecolumn A. By regulating the valve X the ases to betreated can if desired be admitte to the tubes in the vaporizer V at apressure slightly 1120 whilst under the same pressure as that at tionbeing used for bringing pressed gases are which the partial liquefactionof the gases is effected, the gas rich in nitrogen thus obtainedreturning to the place Where the nitrogen containing liquid is producedand the liquid substantially free from nitrogen produced as a result ofthe said progressive rectificaabout by its vaporization the said partialliqueaction.

2. A process according to c aim 1,in which the liquid in the vaporizerat the bottom of the auxiliaryrectification column is heated by passingpart of the compressed gases tobe treated by indirect contact with saidliquid in the said vaporizer whereby the said comliquefaction beingadded to that which collects at the bottom of the principal liquefyingcolumn whilst the gaseous residue from the aforesaid partialliquefaction is delivered at,

an appropriate point tothe principal lique- Mfying column for furthertreatment therein.

3. A process according to claim l, in which the liquid in the vaporizerat the bottom of the auxiliary rectification column is heated bycirculating in indirect contact therewith part of the compressed gasesto be treated, at

a ressure higher than that of the main part o the gases to be treated inthe principal liquefying c`olumn.

4. A process of manufacturing 1 hydrogen, comprising the steps ofpartially quefylng a gaseous mixture containing hydrogen; ex-

tracting the nitrogen-contaming liquid formed durmg the liquefactionoperation;

subjecting it to a progressive vaporization out of the path of thegaseous mixture undergoing liquefaction; and mixing the gas rich innitrogen obtained from the vaporization operation with the gaseousmixture at the point where the nitrogen-containing liquid is collected.

5. A rocess of manufacturing hydrogen, comprising the steps of partiallyliquefying a gaseous mixture containing hydrogen in a main liquefyingcolumn; delivering to an auxlliary liquefymg column, for progressiveVaporization therein, the nitrogen-containing liquid formed andcollecting in the main co umn Aduring the liquefaction operation;returning from the auxiliary column to the portion of the main columnwherein said nitrogen-ccntaining liquid collects, the gas rich partiallyliquefied, the. liquid produced as a result of the partial vin nitrogenobtained from the vaporizing operation; and returning the substantiallynitrogen-ree liquid, which collects in said auxiliary column as a resultof the progressive vaporizing operation, to the vupper part of the maincolumn so as to travel through the' same in counter-current with thehydrogencontaining gaseous mixture and, by its' vaporization, effect thepartial liquefaction of said mixture.

6. A process of separating the constituents of gaseous mixtures, such asthose containing hydrogen, by partial liquefaction, which comprisesprogressively liquefying the gaseous mixture; collecting the liquidcontaining the last liquefied constituent; separately subject-v ing itto a progressive vaporization out of the path of the gaseous mixtureyundergoing liquefaction; and mixin-g the gas obtained by saidvaporization with the gaseous mixture while undergoing liquefaction. v

7. A process of separating theconstituents of gaseous mixtures, 'such asthose v.containing hydrogen, by partial liquefaction, which comprisesprogressively liquefying the gaseous mixture; collecting the liquidcontaining the last liquefied constituent; separately subjecting it to aprogressive vaporization; returning the gas obtained by saidvaporization to vthat part of the liquefaction process where the lastliqueable constituent liquees; and vaporizing the liquid remaining aftersaid Vaporizatlon for assisting in the liquefaction process.

8. A process of separating the constituents of gaseous mixtures, such asthose containing hydrogen, by partial liquefaction, which comprisesprogressively liquefying the gaseous mixture; collecting the liquidcontaining the last liquefied constituent; separately subjecting it to aprogressive vaporwation out of the path of the gaseous mixtureundergoingliquefaction; mixing the gas obtained by said vaporizationwith the gaseous mixture` while undergoing liquefaction and utilizing apart of the gaseous mixture to be treated for effecting the progresslvevaporization.

9. A process of of gaseouslmixtures, such as those containing hydrogen,by partial liquefaction, which comseparating the constituents prisesprogressively liquefying the gaseous mixture; vcollecting the iquidcontainlng the last liquefied constituent; separately subject-j ing itto a progressive vaporization; returning the gas obtained by saidvaporization to that part of the liquefaction process Where the lastliquefahle constituent liqueies; and partially vaporizing the liquidremaining after said vaporizatlon by partially liquefying a part 'of thegaseous mixture treated.

10. A process of separating the constituents of gaseous mixtures, suchas those containing hydrogen, by partial li uefaction, which comprisesprogressively iquefying the. gaseous mixture; collecting the liquicontaining the last liquefied constituent; separately subjecting it to aprogressive vaporization; returning the gas obtained by saidvaporization to that part of the liquefaction process Where the lastliqueable constituent liquelies; partially vaporizing the liquidremaining after said Vaporization by partially liquefying apart of thegaseous mixture treated; and joining the gas .remaining from suchpartial liquefaotion to the main gaseous mixture -unler liquefaction.

In testimony whereof I aiix my signature.

GEORGES CLAUDE.

